对称

Beryl is a hexagonal crystal, and as such has four axes of symmetry.

绿玉石是六角形的水晶，而且同样地有对称的四个轴。

Applying the theory of Bessel function, the exact transfer matrix formulae of the asymmetric free vibration of the circular and annular plate elements with uniform thickness can be obtained.

应用贝塞尔函数理论，求得等厚度圆板和环板单元非对称自由振动传递矩阵的正确公式。

A better idea springs from the weak force , which governs certain nuclear processes, including radioactive beta decay. In 1964, physicists found that the weak force is not quite symmetrical in its dealings with matter and antimatter, resulting in something known as CP violation .

比较好的意见是后来突然提出来的称为"弱力"的理论，这种"弱力"控制了某些核过程，其中也包括了放射性的β衰变。1964年，物理学家发现弱力在处理物质和反物质是不完全对称的，此种结果称为宇称不守恒。

It is shown that baryogenesis via leptogenesis occurs quite naturally, with a single phase (determined from neutrino oscillation data) appearing in leptonic asymmetry and in neutrinoless double beta decay.

而且能很自然地由轻子数破坏产生重子不对称的实验观测值。很有趣的是这类模型中出现在轻子不守恒和无中微子双beta衰变中的相位是一样的。

Design and synthesis of chiral phosphorus ligands and the applications of them in catalytic asymmetric reactions has been a hot topic. Researchers betake themselves to develop novel chiral phosphorus ligands to solve problems that the existing ones cannot do.

中文摘要手性膦配体的设计与合成及其在不对称催化中的应用一直是研究的热点领域，研究人员一直致力于开发新型的手性膦配体来解决已有配体不能解决的问题。

The performance of EFT is investigated, which indicates that time-frequency distributions using single-sided window could not accurately trace the variation of the instantaneous frequency, since their performance depend only on the history of the signal, so they are biased frequency estimator.

提出了基于对称阵元互Wigner分布平均的瞬时频率估计算法，这种方法利用多通道数据对时频分布的瞬时频率估计方法的性能进行了有效的改善，并且能够在低信噪比的条件下获得良好的估计效果， 6。

This paper proposes an algorithm named Small Sample Incremental Biased Learning Algorithm to solve three difficulties of relevance feedback in sketch retrieval, including small sample issue, asymmetry of training data and real-time requirement.

为了解决草图检索相关反馈中小样本训练、数据不对称及实时性要求这3个难点问题，提出了一种小样本增量有偏学习算法。

Based on the analysis of bibliographer and evaluation of the principles of different processes, the novel process for synthesis of the new type of polyheterocyclic disperse dyestuff , unsymmetrical benzodifuranones and its intermediates was studied in the dissertation.

论文在查阅国内外有关文献基础上，对不对称苯并二呋喃酮系新型稠杂环分散染料的分子设计、应用特性及研究进展作了概述，对此类稠杂环分散染料及其中间体的合成路线和方法作了综合评述。

Based on the relation between modal amplitude and phase in the mode conversion of the few mode fiber, a novel configuration of an asymmetric biconical fiber and a fiber mode converter is presented to realize the nonreciprocal propagation in optical fibers. Preliminary feasibility is demonstrated both theoretically and experimentally.

基于少模光纤中模式转换的振幅和相位关系，提出采用不对称双锥光纤与光纤模式转换器的组合结构实现光纤中非互易传输的技术构思，从理论和实验上进行了初步的可行性论证。

The antenna has a composite structure of a cage and an asymmetric biconical structure. The impedance bandwidth and radiation pattern bandwidth are enhanced, and the tilting and ripping of radiation patterns are eliminated.

将笼型与不对称双锥结构相结合，展宽了天线的阻抗和方向图带宽，抑制了天线辐射方向图在宽频带内上翘或裂瓣。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。